I've yet to find the box still...

Sadly I don't have a screenshot, but I have gotten mystery mastery books from the monster park boxes before.

the best thing I got so far is like 10 chaos scrolls and rest I just drop.

I've gotten probably 70 boxes already. I've got the same things as you, but I also got Avarice Pendant scrolls for the other 3 stats and maybe a weapon attack as well (not sure since I just toss them out immediately). I also got the Avarice Pendant- stats are +2 all stats, 50 wep/mag def, 5 upgrades available, and supposedly it can increase the rate of rare item drops in Monster Park if you wear it).

I'm pretty sure the possible box prizes are on OrangeMushroom anyway...

You can get a MMB from the box of greed, but i dont have a screen cuz i used it.... sorry

How do I get these boxes?

Secret recipes too bro

you can get MM from it. sorry no SS :

Does the 1.3x coupon expire?

Does the 1.3x coupon expire?[/quote]
Yes, it expires in 2 days